This invention relates to sailing craft and especially to sailboats having a mast, keel and ballast interconnect through a transfer shaft to stabilize the boat hull.
Sailboats have usually been assembled by using a fixed hull having a fixed mast attached thereto and a fixed keel extending from the bottom and having a ballast substantially rigidly formed to the keel to aid in stabilizing the hull. The keel is heavily weighted to provide a substantial amount of ballast to add stability to the sailboat when under way. With this type of design, the lateral wind force acting on the sails causes the entire vessel to heel with the adverse affects of heeling on the hull increasing the incursion of water and with the asymmetrical underwater hull shape tending to cause veering of the craft off-course while increasing the bow wake and resistance to forward movement. This in turn increases the tendency of the craft to capsize as the stability of the boat is decreased. The heeling of the boat is generally countered by the crew shifting their weight to the opposite side of the hull to prevent the hull from capsizing and to maintain the stability of the hull.
In the past, various approaches have been tried to solve these problems, such as that shown in U.S. Pat. No. 3,972,300, which shows a sailing craft having a one-piece hull design with a unitary mast, keel, and ballast assembly mounted on the hull of the craft so that the mast, keel, and ballast assembly can rotate independently on the hull to permit the hull of the craft to float free of the wind heeling forces. In the U.S. Pat. No. 3,885,512 to Marcil, a catamaran structure is shown in which the mast and sail are also formed as a unitary structure to tilt laterally to port or starboard when the catamaran is underway. The unitary structure of the mast and the keel are rotatably mounted to the platform above the water level in the catamaran which thus reduces the complexities from that found in a conventional sailboat. The Petrovich patent, U.S. Pat. No. 4,610,212, shows another catamaran having a pivotable mast with a downwardly extending section that holds an underwater ballast. The Stoeberl patent, U.S. Pat. No. 3,747,550, shows a plastic sailboat body and keel assembly while the Webster patent, U.S. Pat. No. 667,158, shows a center board for vessels which can be raised and lowered. The Beardsley patent, U.S. Pat. No. 648,911, shows a sailing craft in which a movable mast is connected to an inclined shaft extending through the bottom of the sailboat and to a ballast. The D. Beardsley & F. A. Robinson patent, U.S. Pat. No. 537,667, shows a sailboat in which the wind pressure upon the sails causes the mast to yield and move to leeward by revolving a shaft and bearings which transmits the motion to arms and hence to a ballast without rocking the hull. In U.K. patent application 2,151,195 A to Craig, a pivoting mast for a water borne or land based vehicle is illustrated. In the Dailey patent, U.S. Pat. No. 627,844, a device for lowering and raising smoke stacks is illustrated.
In contrast to these prior art patents, the present invention provides a stable sailboat in which the shifting mast is attached to an elongated transfer shaft at one end which transfer shaft is sealed to the bottom of the boat and has the keel extending through the bottom of the boat and attached thereto which keel has a ballast mounted on the bottom thereof for maintaining the stability of the sailboat.